Roof support frames for mining

ABSTRACT

A roof support frame has a roof bar which is supported on first props connected to a base. A second prop depends from the roof bar and is retractable to enable it to be set on one side or other of the conveyor.

United States Patent Harmsma et a1.

[ Dec. 16, 1975 ROOF SUPPORT FRAMES FOR MINING Inventors: GuenterHarmsma,

Bergkamen-Overberge; Harry Rosenberg, Leudinghausen; Johannes Laabs,Oberaden; Kunibert Becker, Werl, all of Germany Gewerkschaft EisenhutteWestfalia, Westfalia, Germany Filed: Aug. 12, 1974 Appl. No.: 496,687

Assignee:

US. Cl. 61/45 D; 248/357 Int. Cl. E21D 15/44 Field of Search 61/45 D;299/31, 33;

Primary Examirier-Dennis L. Taylor Attorney, Agent, or FirmSughrue,Rothwell, Mion, Zinn & Macpeak 5 7 ABSTRACT A roof support frame has aroof bar which is supported on first props connected to a base. A secondprop depends from the roof bar and is retractable to enable it to be seton one side or other of the conveyor.

6 Claims, 10 Drawing Figures US. Patent Dec. 16,1975 Sheet2of4 3,925,995

mw mm @m I l I I IL ROOF SUPPORT FRAMES FOR MINING BACKGROUND OFINVENTION The invention relates to a support frame. There is a known andwidely used system in which working breast or panel.

One object of the invention is to enable a support frame or the like,capable of being fed forward over the floor of the working, to beconstructed in such a way that theroof can be supported in the workingarea particularly effectively, especially if the mining machines usedpenetrate the face to considerable depths, e.g., .to more than 1 meter.A further object of the invention is to provide an advancing devicewhich is of comparatively moderate overall length but which will Asupport frames or other moving supporting elements nevertheless advancethe frame by a distance comparable with the cutting depth. These andother objects will appear in greater detail from consideration of aspecific embodiment of the invention which will now be described by wayof example and with reference to the accompanying drawings, wherein eachof FIGS. 1 to 3 is a side view of a roof support frame at a respectivestage of advance, and each of FIGS. 40 to 4g is a plan view of adouble-stroke advancing device for use with the support frame shown inFIGS. 1 to 3.

Referring to FIGS. 1 to 3, a longwall mine working includes a mineralface 11, a floor and a roof 19. A scraper chain conveyor 10 extendsalongside the face and conveys to the end of the working mineral whichis removed fromthe face by a shearing machine 12. The shearing machinehas two cutting drums 13 which are adjustable in height and have anaxial length of about 1500 mm. for example. One of the cutting drumsremoves the upper part of the seam while the other removes the lowerpart of the seam. Since the drums are of a substantial length, themachine is unbalanced and is therefore provided with a lateral extension14 which bears against the floor on the face side of the conveyorrearwardly of the lower drum.

The roof of the working is supported by a series of support units orframes, only one of which is shown in FIGS. 1 to 3, but which isidentical to the others.

The support frame has four hydraulic props l6 situated at the comers ofa square and only two of which are shown in the side view. The feet ofthe props 16 rest on a floor bar 17 or are interconnected by some otherdevice bearing against the floor. The upper ends of the props l6 bear aroof bar 18 which supports the roof 19 on the goaf side of the conveyor.The props are flexibly connected to the roof bar and floor bars. Theroof bar 18 forms the main part of the superstructure of the supportframe and is connected by a joint 20 with a further roof bar 21 whichsupports the roof in the working and conveying zones. At least onehydraulic prop 22 is suspended from the roof bar 21 by means of aball-and-socket joint 23, and includes a number of telescope sections.The foot of the prop 22 is fitted with a base plate 24 by means of aball joint. The hydraulic prop 22 is so constructed, in the knownmanner, that it can be retracted by subjecting its annular chambers tohydraulic fluid. Because the prop is suspended from the roof bar 21, thefoot 24 of the prop is raised from the floor 15 during retraction, asshown by the dot-anddash line at 22 in FIG. 2.

The advancing device for shifting the support frame consists of ahydraulic advancing ram 25 having a cylinder articulated at 26 to anattachment 27 which is connected to a T-rail 28 secured to the goaf sideof the conveyor. The piston rod 29 of the ram has a bifurcated end 30which is articulated to a connecting bracket 31. at the rear end of thefloor bar and projecting to the goaf side thereof. The rear prop 16 ofthe support frame and the advancing ram are protected by a shield 32.

The support frame is depicted in FIG. 1 prior to the passage of theshearing machine 12. The roof bar 21 is in a rearward position and theprop 22 is fully extended. As soon as the said machine has passed thesupport frame the advancing prop 22 is raised into the position 22 shownin FIG. 2 and the piston rod 29, retracted into its cylinder so that thesupport frame is shifted towards the work face 11 with the advancingprop depending from the roof bar 21. The prop 22 is thus brought into aposition on the face side of the conveyor 10. The prop 22 is thenextended to engage its base plate 24 with the floor and hold the roofbar 21 against the roof in the zone of the working area.

To advance the conveyor 10, the prop 22 is once again retracted to raiseits base plate 24 from the floor and the ram 25 is actuated to extendits piston rod. The conveyor 10 is thus pushed under the prop 22andagainst the work face, as shown in FIG. 3. The prop 22 is then onceagain extended and set, this time on the goaf side of the conveyor 10.Needless to say, during the shifting of the conveyor 10 the props 16 ofthe support frame are set between the roof and the floor and form thereaction for the shifting process.

A lever arm 33 projects from the rearward end of the roof bar 21 and haspivoted to it at 34 a cylinder 35. The piston rod 36 of the cylinderrests against the lower side of the roof bar 18. By extending thecylinder 35, the roof bar 21 is swung upwards towards the roof 19.During the shifting of the conveyor 10, therefore, the roof bar 21 isheld firmly against the roof, even though the prop 22 has been liftedoff the floor. It is also possible for the roof bar 21, during theshifting of the sup-- port frame, to be kept in contact with the roof bypressurising the cylinder 35. I

The support frame can be fitted with a number of props 22, (e.g., withtwo such props in succession to each other, as viewed in the work facedirection) the props being suspended from one common roof bar 21' orfrom two adjacent roof bars.A number of cylinders.

35 or other pivoting devices for pivoting the roof bar 21 upwards canlikewise be provided. Needless to say, the stroke of the cylinder 25must be made equal to the depth of cut of the ripping machine 12, inorder to enable the support frame and the conveyor to be shifted by adistance corresponding to the depth of cut.- As shown in FIGS. 1 and 3,these conditions are ful-- filled by a shifting cylinder which isextremely longwhen extended and which, on the goaf side, extends as;

far as the stowage compartment.

The advancing device shown in FIGS. 1 to 3 is of a simplified kind tofacilitate understanding of the operation of the frame as a whole. I

In order to reduce the over-all length of the advancing device andnevertheless to obtain a sufficient advance stroke, it is preferred inaccordance with the invention to use a double stroke advancing device ofthe construction shown in FIGS. 4a to 4g.

In FIGS. 4a to 4g the support frame A (from which the prop 22 has beenomitted) is shown in the various phases of the shifting movement, itshydraulic props 16 being interconnected by floor bars 17 comprisingleaftype springs. Between the props 16 is a double-acting shifting ram25 articulated at 26 to the coal face conveyor 10. The stroke of theshifting ram 25 is approximately equal to half the cutting depth of themining machine. Parallel guide bars 50 and 51, which consist of flatbars and along which is guided a sliding block 52 constructed as aslide, are affixed to the two floor bars 17 of the support frame. Thefloor bars are fitted at their rearward ends with brackets 53 which formprolongations of the guide bars 50 and 51 and which are provided withstop lugs 54. The guide bars 50 and 51 are provided with recesses 55 and56 respectively in the vicinity of the brackets 53 and also forwardlythereof. In addition, stops 57 are situated at the front ends of theguide bars. The piston rod 29 of the shifting ram 25 is connected via apin joint 58 with a pressure-and tension-proof, approximately box-shapedcoupling element 59 which bears apivot shaft 60 on which are pivotablymounted two claws 61 and 6 1-. To the sliding block 52 are affixed twobolts 62 and 62' of a link guide, which pass through slots 63 of theclaws. The link guide is so constructed that on the retraction andextension of the shifting ram 25 the claws are moved from a position inwhich'they have been pivoted forwards (FIG. 4b) into a position in whichthey have been pivoted backwards (FIG.- 4c).

FIG. 4a shows the support frame A in the initial position, in which itprops 16 have been set. In order to shift the conveyor 10, the shiftingram 25 is extended as shown in FIG. 4b, the support frame providing thereaction for the shifting ram. In this process the piston rod 29 restsvia the coupling element 59 and the slide block 52, and by means of thestops 24 indicated in FIG. 412, against the lugs 54 of the brackets 53.It may be seen that when the shifting ram 25 is subjected to pressure,the slide block 52 is first of all moved by the extending piston rod 29towards the right, as viewed in the drawings, until the stops 64 of theslide block encounter the lugs 54. In this adjusting movement the claws61 and 61' are pivoted from the piston shown in FIG. 4a into that shownin FIG. 4b.

In FIG. 4b the conveyor has been shifted by a distance corresponding tohalf the cutting depth of the shearing machine. In order to shift theconveyor by a further partial stroke to bring it into engagement withthe new face, the shifting ram is retracted in accordance with FIG. 40.In this process the slide block 52 is drawn forwards in the directionshown by the arrow S, by the retracting piston rod 26, and the claws 61and 61' are pivoted, via the coupling element 59 and the link guide 62,63, into the position shown in FIG. 40. When the shifting ram 25 hasbeen fully retracted, the claws 61 and 61 are situated in the vicinityof the recesses 56 of the guide bars 51. If the shifting ram 25 is onceagain extended, then the claws 61 and 61 are first of all spreadoutwards, at the beginning of the extending movement of the piston rod,as shown in FIG. 4d, in such a way that the said claws come to rest bytheir contact surfaces 65 against stops 66, which are formed by the endfaces of the guide bars in the vicinity of the recesses 56. The pistonrod 29 of the shifting ram 25 now rests against the support frame, viathe pivot claws 61 and 61 and the stops 65 and 66, so that on thefurther extension of the shifting ram the conveyor 10 is shifted by afurther partial stroke. At the end of the shifting process the conveyor10 has been shifted to a distance corresponding to the complete advancemovement (FIG. 4d).

The support frame A is then drawn up into position, in two partialstrokes. For this purpose the shifting ram 25 is retracted, inaccordance with FIG. 4e. The slide block 52 is first of all drawnforwards until it encounters the front stop lug 57, the claws 61 and 61being at the same time pivoted inwards. The retracting piston rod 29then causes the slide block 52, which is resting against the stops 57,to accompany its movement in the direction shown by the arrow S. Whenthe piston rod has been fully retracted, the support frame A has beenshifted by a distance corresponding to half the advance movement (FIG.42).

In order to shift the support frame A by afurther partial stroke, theshifting ram 25 is once again extended. The piston rod 29 moves theslide block 52 back into the position shown in FIG. 4f in which processthe claws 61 and 61', at the beginning of the outward movement of thepiston rod, are pivoted from the position shown in FIG. 42 into thatshown in FIG. 4f. To enable the claws to be pivoted in this manner, theguide bars 50 and 51 are provided with the recesses 56. If the shiftingram 25 is now once again extended when in the position shown in FIG. 4f,then the claws 61 and 61 are spread outwards at the beginning of theretracting stroke of the piston rod, so that their contact surfaces 65come to rest against stops 66 of the guide bars and formed by the frontedges of the recesses 55 of the said guide bars. On further retractionof the piston rod 29, the support frame A is drawn up to the conveyor10, via the pivot claws which have been spread outwards. The supportframe A now once again occupies the basic position shown in FIG. 4a.

It can be seen that the slide block'52, in conjunction with the lockingdevice consisting of the claws, forms an adjustable stop providingreaction for the shifting cylinder 25 and its piston rod 29, and that inthis manner the conveyor 10 and the support frame A can each be shiftedin two partial strokes, the action of locking the slide block 52 and theclaws in position in relation to the support frame being carried outautomatically on the retraction and extension of the piston rod 29.

What we claim is:

l. A longwall mining system comprising: a conveyor, a mining machineguided for movement along the conveyor, and a series of roof supportsarranged alongside the conveyor; at least one roof support comprising abase, at least one first prop extending upwardly from the base, a roofbar means supported on said at least one first prop, at least one secondprop depending from said roof bar means forwardly of said at least onefirst prop, said at least one second prop being retractable from afioorengaging position into a position spaced from the floor by adistance at least equal to the height of the conveyor, means foradvancing the roof support in order to displace the said at least onesecond prop from a position rearwardly of the conveyor to a positionforwardly of the conveyor, said means including a fluid operated rammeans having a stroke shorter than the advance step of the roof support,said ram means being coupled between the conveyor and a sliding block,the base defining a guideway for the sliding block, said guideway havingassociated therewith a first stop means for supporting the sliding blockagainst the force of the ram means during an initial extension strokethereof and second stop means for supporting the sliding block againstthe force of the ram means during a subsequent extension stroke thereof,said second stop means being located forwardly of the first stop meansand being cooperable with a locking device adapted to be moved into anactive position upon extension of the ram means during said subsequentextension stroke.

2. A longwall mining system comprising: a conveyor, a mining machineguided for movement along the conveyor, and a series of roof supportsarranged alongside the conveyor; at least one roof support comprising abase, at least one first prop extending upwardly from the base, a roofbar means supported on said at least one first prop, at least one secondprop depending from said roof bar means forwardly of said at least onefirst prop, said at least one second prop being retractable from a floorengaging position into a position spaced from the floor by a distance atleast equal to the height of the conveyor, means for advancing the roofsupport in order to displace the said at least one second prop from aposition rearwardly of the conveyor to a posi tion forwardly of theconveyor, said means including a fluid operated ram means having astroke shorter than the advance step of the roof support, a slidingblock guided for movement along said base, a locking device pivoted onsaid sliding block, said ram means being coupled at one end to theconveyor and at its other end to the locking device, extension of saidram causing said locking means to pivot into an active position, and aguideway for the sliding block, said guideway including rearward stopmeans for engagement with the sliding block and forward stop means forengagement with the locking device when said locking device has beenpivoted into its active position.

3. Support frame in accordance with claim 2 characterised by the factthat the locking device consists of two pivot claws which spreadoutwards during extension of the ram.

4. Support frame in accordance with claim 3, characterized by the factthat the pivot claws are pivotable about a shaft coupled to the ram andmovable in relation to the sliding block in the direction of the strokeof the ram and are guided in relation to the sliding block by means oflink guides.

5. Support frame in accordance with claim 4, characterized by the factthat the locking device is adjustable from a position in which, in orderto move the conveyor, it supports the ram in relation to the stayedsupport frame, to a position in which it couples the ram to the supportframe in order to move the latter up into position.

6. Support frame in accordance with claim 5, characterized by the factthat the sliding block is guided on parallel guide bars of the supportframe, the said bars being provided with recesses to enable the pivotclaws to be pivoted through, and with stop faces as a means ofsupporting the pivot claws.

1. A longwall mining system comprising: a conveyor, a mining machineguided for movement along the conveyor, and a series of roof supportsarranged alongside the conveyor; at least one roof support comprising abase, at least one first prop extending upwardly from the base, a roofbar means supported on said at least one first prop, at least one secondprop depending from said roof bar means forwardly of said at least onefirst prop, said at least one second prop being retractable from a floorengaging position into a position spaced from the floor by a distance atleast equal to the height of the conveyor, means for advancing the roofsupport in order to displace the said at least one second prop from aposition rearwardly of the conveyor to a position forwardly of theconveyor, said means including a fluid operated ram means having astroke shorter than the advance step of the roof support, said ram meansbeing coupled between the conveyor and a sliding block, the basedefining a guideway for the sliding block, said guideway havingassociated therewith a first stop means for supporting the sliding blockagainst the force of the ram means during an initial extension strokethereof and second stop means for supporting the sliding block againstthe force of the ram means during a subsequent extension stroke thereof,said second stop means being located forwardly of the first stop meansand being cooperable with a locking device adapted to be moved into anactive position upon extension Of the ram means during said subsequentextension stroke.
 2. A longwall mining system comprising: a conveyor, amining machine guided for movement along the conveyor, and a series ofroof supports arranged alongside the conveyor; at least one roof supportcomprising a base, at least one first prop extending upwardly from thebase, a roof bar means supported on said at least one first prop, atleast one second prop depending from said roof bar means forwardly ofsaid at least one first prop, said at least one second prop beingretractable from a floor engaging position into a position spaced fromthe floor by a distance at least equal to the height of the conveyor,means for advancing the roof support in order to displace the said atleast one second prop from a position rearwardly of the conveyor to aposition forwardly of the conveyor, said means including a fluidoperated ram means having a stroke shorter than the advance step of theroof support, a sliding block guided for movement along said base, alocking device pivoted on said sliding block, said ram means beingcoupled at one end to the conveyor and at its other end to the lockingdevice, extension of said ram causing said locking means to pivot intoan active position, and a guideway for the sliding block, said guidewayincluding rearward stop means for engagement with the sliding block andforward stop means for engagement with the locking device when saidlocking device has been pivoted into its active position.
 3. Supportframe in accordance with claim 2 characterised by the fact that thelocking device consists of two pivot claws which spread outwards duringextension of the ram.
 4. Support frame in accordance with claim 3,characterized by the fact that the pivot claws are pivotable about ashaft coupled to the ram and movable in relation to the sliding block inthe direction of the stroke of the ram and are guided in relation to thesliding block by means of link guides.
 5. Support frame in accordancewith claim 4, characterized by the fact that the locking device isadjustable from a position in which, in order to move the conveyor, itsupports the ram in relation to the stayed support frame, to a positionin which it couples the ram to the support frame in order to move thelatter up into position.
 6. Support frame in accordance with claim 5,characterized by the fact that the sliding block is guided on parallelguide bars of the support frame, the said bars being provided withrecesses to enable the pivot claws to be pivoted through, and with stopfaces as a means of supporting the pivot claws.